Aripiprazole, i.e., 7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butoxy}-3,4-dihydrocarbostyryl or 7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butoxy}-3,4-dihydro-2(1H)-quinolinone, is an atypical antipsychotic agent useful for the treatment of schizophrenia (patent document 1).
Schizophrenia is a mental disease of a general type, which is characterized by delusion, hallucination and complete withdrawal from others. The sign of schizophrenia generally occurs between age 16 to 25, and schizophrenia is developed in one out of one hundred in the world. Schizophrenia is more often seen than Alzheimer's disease, multiple sclerosis, insulin dependent diabetes and muscular dystrophy. It is known that early diagnosis and treatment can markedly improve recovery and outcome, and further, a therapeutic intervention at an early stage can avoid costly hospitalization, and the like.
Generally, the starting daily dose of aripiprazole is 6-12 mg, and the daily maintenance dose is 6-24 mg, for an adult, and is orally administered in one or two portions a day (non-patent document 1). In addition, aripiprazole has a long half-life in blood of about 65 hr in healthy adults, and is an extremely superior medicament that is not easily influenced by diet.
Therefore, the development of a new administration method of aripiprazole has been tried, and a transdermal treatment absorption system (TTS) in the form of a plaster has been tried in addition to the oral administration route (patent document 2). However, specific effect is not at all described, and the characteristic of a transdermal absorption preparation is not clear.
While a transdermal absorption preparation containing a basic drug including aripiprazole and a copolymer containing polyvinylpyrrolidone as a main component is referred to, no specific Example is given and only risperidone is described (patent document 3).
When risperidone is used as a basic drug, an organic acid is added as a melting point lowering agent, and a superior amount of the organic acid to be used is described to be not less than the equimolar of risperidone (for example, 2- to 3-fold molar amount) (patent document 4).
However, a specific combination and an effect of aripiprazole and an organic acid are not considered at all. In addition, the transdermal absorbability derived from an organic acid salt of aripiprazole is not known at all.